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Nadal has 17 while Djokovic has stalled on 12 since completing the career Grand Slam at Roland Garros in 2016. It also highlights the calibre of player Anderson is.
That blip was enough for Nadal, chasing an 18th Grand Slam title, to surrender his first set of the championships.
"Friday is another important match against an opponent who is one of the most hard ones that you can face".
As Nadal looks ahead to the semi-finals, Del Potro heads for his next tournament. Having reached the US Open final previous year, Anderson will also be one-up on Isner in the big-stage experience department.
Great match, an emotional match for both of us and for the fans, too.
Del Potro trails Nadal 10-5 in head-to-head meetings - his five wins all coming on hardcourts. "I'm a different person, different player today", Djokovic said.
Playing him is always a big challenge.
"I have done a lot of things well since I came back from injury".
"Congratulations to Kevin Anderson for reaching the men's singles semi-finals", Ramaphosa tweeted on Thursday.
"I just try to build the momentum". It was an honour to share the court with you.
Nadal, the No. 2 seed, won the first set before dropping the second to his Argentine counterpart.
"This photo says it all", wrote Juan Martin del Potro on his Instagram page.
On Wednesday, we saw Nadal's confidence, and even his intensity, briefly wane when Juan Martin del Potro forced his way into their quarterfinal late in the second set. Nadal is through to a Grand Slam semi-final for the fifth time since turning 30 while Djokovic has reached the last-four at a major for the first time since his 30th birthday.
After seven weeks out with a serious knee injury, many doubted if Nadal would regain his crown as the "King of Clay".
While the Federer exit, to South African Kevin Anderson, losing 13-11 in the final set, is what will sadden most viewers and grab what there are of tennis headlines today, Nadal coming from two sets to one down against perennial almost man Juan Martin Del Potro produced perhaps the most incredible tennis of the day, and definitely the moment of the tournament.
Both men are in the semi-finals at Wimbledon for the first time. I know in the semi-finals of Wimbledon you will not have an easy opponent.
"I'm very, very happy to be in this position right now", said the ninth seed, who has never played on Centre Court at Wimbledon.
"Beating Roger Federer at Wimbledon is definitely one I'm going to remember".
"I am not that good to have the chance to think about all the things going on outside".